#include "cppdefs.h"
#if defined TANGENT || defined TL_IOMS
      SUBROUTINE tl_wrt_his (ng)
!
!svn $Id$
!================================================== Hernan G. Arango ===
!  Copyright (c) 2002-2018 The ROMS/TOMS Group                         !
!    Licensed under a MIT/X style license                              !
!    See License_ROMS.txt                                              !
!=======================================================================
!                                                                      !
!  This routine writes requested tangent linear model fields into      !
!  into tangent history NetCDF file.                                   !
!                                                                      !
!=======================================================================
!
      USE mod_param
      USE mod_parallel
# ifdef ADJUST_BOUNDARY
      USE mod_boundary
# endif
# ifdef SOLVE3D
      USE mod_coupling
# endif
# if defined ADJUST_STFLUX || defined ADJUST_WSTRESS || \
     defined FORCING_SV    || defined STOCHASTIC_OPT || \
     defined HESSIAN_SO    || defined HESSIAN_FSV
      USE mod_forces
# endif
      USE mod_grid
      USE mod_iounits
# ifdef SOLVE3D
      USE mod_mixing
# endif
      USE mod_ncparam
      USE mod_netcdf
      USE mod_ocean
      USE mod_scalars
# if defined SEDIMENT_NOT_YET || defined BBL_MODEL_NOT_YET
      USE mod_sediment
# endif
      USE mod_stepping
!
      USE nf_fwrite2d_mod,     ONLY : nf_fwrite2d
# ifdef ADJUST_BOUNDARY
      USE nf_fwrite2d_bry_mod, ONLY : nf_fwrite2d_bry
# endif
# ifdef SOLVE3D
      USE nf_fwrite3d_mod,     ONLY : nf_fwrite3d
#  ifdef ADJUST_BOUNDARY
      USE nf_fwrite3d_bry_mod, ONLY : nf_fwrite3d_bry
#  endif
# endif
      USE strings_mod,         ONLY : FoundError
!
      implicit none
!
!  Imported variable declarations.
!
      integer, intent(in) :: ng
!
!  Local variable declarations.
!
      integer :: LBi, UBi, LBj, UBj
# ifdef ADJUST_BOUNDARY
      integer :: LBij, UBij
# endif
      integer :: Fcount, gfactor, gtype, status
# ifdef SOLVE3D
      integer :: i, itrc, j, k, tile
# endif
      real(r8) :: scale
      real(r8) :: Tval(1)
!
      LBi=LBOUND(GRID(ng)%h,DIM=1)
      UBi=UBOUND(GRID(ng)%h,DIM=1)
      LBj=LBOUND(GRID(ng)%h,DIM=2)
      UBj=UBOUND(GRID(ng)%h,DIM=2)
# ifdef ADJUST_BOUNDARY
      LBij=BOUNDS(ng)%LBij
      UBij=BOUNDS(ng)%UBij
# endif
!
      SourceFile=__FILE__
!
!-----------------------------------------------------------------------
!  Write out tangent linear fields.
!-----------------------------------------------------------------------
!
      IF (FoundError(exit_flag, NoError, __LINE__,                      &
     &               __FILE__)) RETURN
!
!  Set grid type factor to write full (gfactor=1) fields or water
!  points (gfactor=-1) fields only.
!
# if defined WRITE_WATER && defined MASKING
        gfactor=-1
# else
        gfactor=1
# endif
!
!  Set time record index.
!
      TLM(ng)%Rindex=TLM(ng)%Rindex+1
      Fcount=TLM(ng)%Fcount
      TLM(ng)%Nrec(Fcount)=TLM(ng)%Nrec(Fcount)+1
!
!  If requested, set time index to recycle time records in the tangent
!  linear file.
!
      IF (LcycleTLM(ng)) THEN
        TLM(ng)%Rindex=MOD(TLM(ng)%Rindex-1,2)+1
      END IF
!
!  Write out model time (s).
!
      IF (LwrtPER(ng)) THEN
        Tval(1)=REAL(TLM(ng)%Rindex,r8)*day2sec
      ELSE
        Tval(1)=time(ng)
      END IF
      CALL netcdf_put_fvar (ng, iTLM, TLM(ng)%name,                     &
     &                      TRIM(Vname(1,idtime)), tval,                &
     &                      (/TLM(ng)%Rindex/), (/1/),                  &
     &                      ncid = TLM(ng)%ncid,                        &
     &                      varid = TLM(ng)%Vid(idtime))
      IF (FoundError(exit_flag, NoError, __LINE__,                      &
     &               __FILE__)) RETURN

# ifdef ADJUST_WSTRESS
!
!  Write out surface U-momentum stress.  Notice that the stress has its
!  own fixed time-dimension (of size Nfrec) to allow 4DVAR adjustments
!  at other times in addition to initialization time.
!
      scale=1.0                             ! m2/s2
      gtype=gfactor*u3dvar
      status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idUsms),   &
     &                   TLM(ng)%Rindex, gtype,                         &
     &                   LBi, UBi, LBj, UBj, 1, Nfrec(ng), scale,       &
#  ifdef MASKING
     &                   GRID(ng) % umask,                              &
#  endif
     &                   FORCES(ng) % tl_ustr(:,:,:,Lfout(ng)))
      IF (FoundError(status, nf90_noerr, __LINE__,                      &
     &               __FILE__)) THEN
        IF (Master) THEN
          WRITE (stdout,10) TRIM(Vname(1,idUsms)), Lfout(ng)
        END IF
        exit_flag=3
        ioerror=status
        RETURN
      END IF
!
!  Write out surface V-momentum stress.
!
      scale=1.0                             ! m2/s2
      gtype=gfactor*v3dvar
      status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idVsms),   &
     &                   TLM(ng)%Rindex, gtype,                         &
     &                   LBi, UBi, LBj, UBj, 1, Nfrec(ng), scale,       &
#  ifdef MASKING
     &                   GRID(ng) % vmask,                              &
#  endif
     &                   FORCES(ng) % tl_vstr(:,:,:,Lfout(ng)))
      IF (FoundError(status, nf90_noerr, __LINE__,                      &
     &               __FILE__)) THEN
        IF (Master) THEN
          WRITE (stdout,10) TRIM(Vname(1,idVsms)), Lfout(ng)
        END IF
        exit_flag=3
        ioerror=status
        RETURN
      END IF
# endif
# if defined ADJUST_STFLUX && defined SOLVE3D
!
!  Write out surface net tracers fluxes. Notice that fluxes have their
!  own fixed time-dimension (of size Nfrec) to allow 4DVAR adjustments
!  at other times in addition to initialization time.
!
      DO itrc=1,NT(ng)
        IF (Lstflux(itrc,ng)) THEN
          scale=1.0_r8                      ! kinematic flux units
          gtype=gfactor*r3dvar
          status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid,                    &
     &                       TLM(ng)%Vid(idTsur(itrc)),                 &
     &                       TLM(ng)%Rindex, gtype,                     &
     &                       LBi, UBi, LBj, UBj, 1, Nfrec(ng), scale,   &
#  ifdef MASKING
     &                       GRID(ng) % rmask,                          &
#  endif
     &                       FORCES(ng)% tl_tflux(:,:,:,Lfout(ng),itrc))
          IF (FoundError(status, nf90_noerr, __LINE__,                  &
     &                   __FILE__)) THEN
            IF (Master) THEN
              WRITE (stdout,10) TRIM(Vname(1,idTsur(itrc))), Lfout(ng)
            END IF
            exit_flag=3
            ioerror=status
            RETURN
          END IF
        END IF
      END DO
# endif
# if defined FORCING_SV || defined STOCHASTIC_OPT || \
     defined HESSIAN_SO    || defined HESSIAN_FSV
!
!  Write out surface U-momentum stress.
!
      IF (Hout(idUsms,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*u2dvar
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idUsms), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#  ifdef MASKING
     &                     GRID(ng) % umask,                            &
#  endif
     &                     FORCES(ng) % tl_sustr)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idUsms)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
!
!  Write out surface V-momentum stress.
!
      IF (Hout(idVsms,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*v2dvar
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idVsms), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#  ifdef MASKING
     &                     GRID(ng) % vmask,                            &
#  endif
     &                     FORCES(ng) % tl_svstr)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idVsms)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
#  ifdef SOLVE3D
!
!  Write out net surface active tracer fluxes.
!
      DO itrc=1,NT(ng)
        IF (Hout(idTsur(itrc),ng)) THEN
          scale=1.0_r8
          gtype=gfactor*r2dvar
          status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid,                    &
     &                       TLM(ng)%Vid(idTsur(itrc)),                 &
     &                       TLM(ng)%Rindex, gtype,                     &
     &                       LBi, UBi, LBj, UBj, scale,                 &
#   ifdef MASKING
     &                       GRID(ng) % rmask,                          &
#   endif
     &                       FORCES(ng) % tl_stflx(:,:,itrc))
          IF (FoundError(status, nf90_noerr, __LINE__,                  &
     &                   __FILE__)) THEN
            IF (Master) THEN
              WRITE (stdout,10) TRIM(Vname(1,idTsur(itrc))),            &
     &                          TLM(ng)%Rindex
            END IF
            exit_flag=3
            ioerror=status
            RETURN
          END IF
        END IF
      END DO
#  endif
# endif
!
!  Write out free-surface (m)
!
      IF (Hout(idFsur,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*r2dvar
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idFsur), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
# ifdef MASKING
     &                     GRID(ng) % rmask,                            &
# endif
# ifdef WET_DRY
     &                     OCEAN(ng) % tl_zeta(:,:,KOUT),               &
     &                     SetFillVal = .FALSE.)
# else
#  ifdef FORCING_SV
     &                     OCEAN(ng) % f_zeta(:,:))
#  else
     &                     OCEAN(ng) % tl_zeta(:,:,KOUT))
#  endif
# endif
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idFsur)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
# if defined FORWARD_WRITE && defined FORWARD_RHS
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idRzet), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#  ifdef MASKING
     &                     GRID(ng) % rmask,                            &
#  endif
     &                     OCEAN(ng) % tl_rzeta(:,:,KOUT))
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idRzet)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
# endif
      END IF

# ifdef ADJUST_BOUNDARY
!
!  Write out free-surface open boundaries.
!
      IF (ANY(Lobc(:,isFsur,ng))) THEN
        scale=1.0_r8
        status=nf_fwrite2d_bry (ng, iTLM, TLM(ng)%name, TLM(ng)%ncid,   &
     &                          Vname(1,idSbry(isFsur)),                &
     &                          TLM(ng)%Vid(idSbry(isFsur)),            &
     &                          TLM(ng)%Rindex, r2dvar,                 &
     &                          LBij, UBij, Nbrec(ng), scale,           &
     &                          BOUNDARY(ng) % tl_zeta_obc(LBij:,:,:,   &
     &                                                     Lbout(ng)))
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idSbry(isFsur))),            &
     &                        TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
# endif
!
!  Write out 2D U-momentum component (m/s).
!
      IF (Hout(idUbar,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*u2dvar
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idUbar), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
# ifdef MASKING
     &                     GRID(ng) % umask_full,                       &
# endif
# ifdef FORCING_SV
     &                     OCEAN(ng) % f_ubar(:,:))
# else
     &                     OCEAN(ng) % tl_ubar(:,:,KOUT))
# endif
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idUbar)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
# ifdef FORWARD_WRITE
#  ifdef FORWARD_RHS
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idRu2d), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#   ifdef MASKING
     &                     GRID(ng) % umask_full,                       &
#   endif
     &                     OCEAN(ng) % tl_rubar(:,:,KOUT))
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idRu2d)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#  endif
#  ifdef SOLVE3D
#   ifdef FORWARD_RHS
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idRuct), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#    ifdef MASKING
     &                     GRID(ng) % umask_full,                       &
#    endif
     &                     COUPLING(ng) % tl_rufrc)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idRuct)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#   endif
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idUfx1), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#   ifdef MASKING
     &                     GRID(ng) % umask_full,                       &
#   endif
     &                     COUPLING(ng) % tl_DU_avg1)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idUfx1)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idUfx2), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#   ifdef MASKING
     &                     GRID(ng) % umask_full,                       &
#   endif
     &                     COUPLING(ng) % tl_DU_avg2)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idUfx2)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#  endif
# endif
      END IF

# ifdef ADJUST_BOUNDARY
!
!  Write out 2D U-momentum component open boundaries.
!
      IF (ANY(Lobc(:,isUbar,ng))) THEN
        scale=1.0_r8
        status=nf_fwrite2d_bry (ng, iTLM, TLM(ng)%name, TLM(ng)%ncid,   &
     &                          Vname(1,idSbry(isUbar)),                &
     &                          TLM(ng)%Vid(idSbry(isUbar)),            &
     &                          TLM(ng)%Rindex, u2dvar,                 &
     &                          LBij, UBij, Nbrec(ng), scale,           &
     &                          BOUNDARY(ng) % tl_ubar_obc(LBij:,:,:,   &
     &                                                     Lbout(ng)))
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idSbry(isUbar))),            &
     &                        TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
# endif
!
!  Write out 2D V-momentum component (m/s).
!
      IF (Hout(idVbar,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*v2dvar
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idVbar), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
# ifdef MASKING
     &                     GRID(ng) % vmask_full,                       &
# endif
# ifdef FORCING_SV
     &                     OCEAN(ng) % f_vbar(:,:))
# else
     &                     OCEAN(ng) % tl_vbar(:,:,KOUT))
# endif
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idVbar)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
# ifdef FORWARD_WRITE
#  ifdef FORWARD_RHS
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idRv2d), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#   ifdef MASKING
     &                     GRID(ng) % vmask_full,                       &
#   endif
     &                     OCEAN(ng) % tl_rvbar(:,:,KOUT))
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idRv2d)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#  endif
#  ifdef SOLVE3D
#   ifdef FORWARD_RHS
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idRvct), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#    ifdef MASKING
     &                     GRID(ng) % vmask_full,                       &
#    endif
     &                     COUPLING(ng) % tl_rvfrc)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idRvct)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#   endif
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idVfx1), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#   ifdef MASKING
     &                     GRID(ng) % vmask_full,                       &
#   endif
     &                     COUPLING(ng) % tl_DV_avg1)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idVfx1)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
        status=nf_fwrite2d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idVfx2), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, scale,                   &
#   ifdef MASKING
     &                     GRID(ng) % vmask_full,                       &
#   endif
     &                     COUPLING(ng) % tl_DV_avg2)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idVfx2)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#  endif
# endif
      END IF

# ifdef ADJUST_BOUNDARY
!
!  Write out 2D V-momentum component open boundaries.
!
      IF (ANY(Lobc(:,isVbar,ng))) THEN
        scale=1.0_r8
        status=nf_fwrite2d_bry (ng, iTLM, TLM(ng)%name, TLM(ng)%ncid,   &
     &                          Vname(1,idSbry(isVbar)),                &
     &                          TLM(ng)%Vid(idSbry(isVbar)),            &
     &                          TLM(ng)%Rindex, v2dvar,                 &
     &                          LBij, UBij, Nbrec(ng), scale,           &
     &                          BOUNDARY(ng) % tl_vbar_obc(LBij:,:,:,   &
     &                                                     Lbout(ng)))
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idSbry(isVbar))),            &
     &                        TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
# endif
# ifdef SOLVE3D
!
!  Write out 3D U-momentum component (m/s).
!
      IF (Hout(idUvel,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*u3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idUvel), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 1, N(ng), scale,         &
#  ifdef MASKING
     &                     GRID(ng) % umask_full,                       &
#  endif
#  ifdef FORCING_SV
     &                     OCEAN(ng) % f_u(:,:,:))
#  else
     &                     OCEAN(ng) % tl_u(:,:,:,NOUT))
#  endif
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idUvel)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#  if defined FORWARD_WRITE && defined FORWARD_RHS
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idRu3d), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 1, N(ng), scale,         &
#   ifdef MASKING
     &                     GRID(ng) % umask_full,                       &
#   endif
     &                     OCEAN(ng) % tl_ru(:,:,:,NOUT))
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idRu3d)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#  endif
      END IF

#  ifdef ADJUST_BOUNDARY
!
!  Write out 3D U-momentum component open boundaries.
!
      IF (ANY(Lobc(:,isUvel,ng))) THEN
        scale=1.0_r8
        status=nf_fwrite3d_bry (ng, iTLM, TLM(ng)%name, TLM(ng)%ncid,   &
     &                          Vname(1,idSbry(isUvel)),                &
     &                          TLM(ng)%Vid(idSbry(isUvel)),            &
     &                          TLM(ng)%Rindex, u3dvar,                 &
     &                          LBij, UBij, 1, N(ng), Nbrec(ng), scale, &
     &                          BOUNDARY(ng) % tl_u_obc(LBij:,:,:,:,    &
     &                                                  Lbout(ng)))
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idSbry(isUvel))),            &
     &                        TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
#  endif
!
!  Write out 3D V-momentum component (m/s).
!
      IF (Hout(idVvel,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*v3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idVvel), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 1, N(ng), scale,         &
#  ifdef MASKING
     &                     GRID(ng) % vmask_full,                       &
#  endif
#  ifdef FORCING_SV
     &                     OCEAN(ng) % f_v(:,:,:))
#  else
     &                     OCEAN(ng) % tl_v(:,:,:,NOUT))
#  endif
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idVvel)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#  if defined FORWARD_WRITE && defined FORWARD_RHS
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idRv3d), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 1, N(ng), scale,         &
#   ifdef MASKING
     &                     GRID(ng) % vmask_full,                       &
#   endif
     &                     OCEAN(ng) % tl_rv(:,:,:,NOUT))
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idRv3d)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#  endif
      END IF

#  ifdef ADJUST_BOUNDARY
!
!  Write out 3D V-momentum component open boundaries.
!
      IF (ANY(Lobc(:,isVvel,ng))) THEN
        scale=1.0_r8
        status=nf_fwrite3d_bry (ng, iTLM, TLM(ng)%name, TLM(ng)%ncid,   &
     &                          Vname(1,idSbry(isVvel)),                &
     &                          TLM(ng)%Vid(idSbry(isVvel)),            &
     &                          TLM(ng)%Rindex, v3dvar,                 &
     &                          LBij, UBij, 1, N(ng), Nbrec(ng), scale, &
     &                          BOUNDARY(ng) % tl_v_obc(LBij:,:,:,:,    &
     &                                                  Lbout(ng)))
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idSbry(isVvel))),            &
     &                        TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
#  endif
!
!  Write out tracer type variables.
!
      DO itrc=1,NT(ng)
        IF (Hout(idTvar(itrc),ng)) THEN
          scale=1.0_r8
          gtype=gfactor*r3dvar
          status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Tid(itrc), &
     &                       TLM(ng)%Rindex, gtype,                     &
     &                       LBi, UBi, LBj, UBj, 1, N(ng), scale,       &
#  ifdef MASKING
     &                       GRID(ng) % rmask,                          &
#  endif
#  ifdef FORCING_SV
     &                       OCEAN(ng) % f_t(:,:,:,itrc))
#  else
     &                       OCEAN(ng) % tl_t(:,:,:,NOUT,itrc))
#  endif
          IF (FoundError(status, nf90_noerr, __LINE__,                  &
     &                   __FILE__)) THEN
            IF (Master) THEN
              WRITE (stdout,10) TRIM(Vname(1,idTvar(itrc))),            &
     &                          TLM(ng)%Rindex
            END IF
            exit_flag=3
            ioerror=status
            RETURN
          END IF
        END IF
      END DO

#  ifdef ADJUST_BOUNDARY
!
!  Write out tracers open boundaries.
!
      DO itrc=1,NT(ng)
        IF (ANY(Lobc(:,isTvar(itrc),ng))) THEN
          scale=1.0_r8
          status=nf_fwrite3d_bry (ng, iTLM, TLM(ng)%name, TLM(ng)%ncid, &
     &                            Vname(1,idSbry(isTvar(itrc))),        &
     &                            TLM(ng)%Vid(idSbry(isTvar(itrc))),    &
     &                            TLM(ng)%Rindex, r3dvar,               &
     &                            LBij, UBij, 1, N(ng), Nbrec(ng),      &
     &                            scale,                                &
     &                            BOUNDARY(ng) % tl_t_obc(LBij:,:,:,:,  &
     &                                                Lbout(ng),itrc))
          IF (FoundError(status, nf90_noerr, __LINE__,                  &
     &                   __FILE__)) THEN
            IF (Master) THEN
              WRITE (stdout,10) TRIM(Vname(1,idSbry(isTvar(itrc)))),    &
     &                          TLM(ng)%Rindex
            END IF
            exit_flag=3
            ioerror=status
            RETURN
          END IF
        END IF
      END DO
#  endif
!
!  Write out density anomaly.
!
      IF (Hout(idDano,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*r3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idDano), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 1, N(ng), scale,         &
#  ifdef MASKING
     &                     GRID(ng) % rmask,                            &
#  endif
     &                     OCEAN(ng) % tl_rho)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idDano)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF

#  if defined FORWARD_MIXING     && \
     (defined BVF_MIXING     || defined GLS_MIXING  || \
      defined LMD_MIXING     || defined MY25_MIXING)
!
!  Write out vertical viscosity coefficient.
!
      IF (Hout(idVvis,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*w3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idVvis), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 0, N(ng), scale,         &
#   ifdef MASKING
     &                     GRID(ng) % rmask,                            &
#   endif
#   ifdef WEAK_CONSTRAINT
     &                     MIXING(ng) % Akv,                            &
#   else
     &                     MIXING(ng) % tl_Akv,                         &
#   endif
     &                     SetFillVal = .FALSE.)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idVvis)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
!
!  Write out vertical diffusion coefficient for potential temperature.
!
      IF (Hout(idTdif,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*w3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idTdif), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 0, N(ng), scale,         &
#   ifdef MASKING
     &                     GRID(ng) % rmask,                            &
#   endif
#   ifdef WEAK_CONSTRAINT
     &                     MIXING(ng) % Akt(:,:,:,itemp),               &
#   else
     &                     MIXING(ng) % tl_Akt(:,:,:,itemp),            &
#   endif
     &                     SetFillVal = .FALSE.)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idTdif)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
#   ifdef SALINITY
!
!  Write out vertical diffusion coefficient for salinity.
!
      IF (Hout(idSdif,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*w3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idSdif), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 0, N(ng), scale,         &
#    ifdef MASKING
     &                     GRID(ng) % rmask,                            &
#    endif
#    ifdef WEAK_CONSTRAINT
     &                     MIXING(ng) % Akt(:,:,:,isalt),               &
#    else
     &                     MIXING(ng) % tl_Akt(:,:,:,isalt),            &
#    endif
     &                     SetFillVal = .FALSE.)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idSdif)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
#   endif
#   if defined GLS_MIXING_NOT_YET || defined MY25_MIXING_NOT_YET
!
!  Write out turbulent kinetic energy.
!
      IF (Hout(idMtke,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*w3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idMtke), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 0, N(ng), scale,         &
#    ifdef MASKING
     &                     GRID(ng) % rmask,                            &
#    endif
     &                     MIXING(ng) % tl_tke(:,:,:,NOUT),             &
     &                     SetFillVal = .FALSE.)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idMtke)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF

        scale=1.0_r8
        gtype=gfactor*w3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idVmKK), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 0, N(ng), scale,         &
#    ifdef MASKING
     &                     GRID(ng) % rmask,                            &
#    endif
     &                     MIXING(ng) % tl_Akk)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idVmKK)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
      END IF
!
!  Write out turbulent length scale field.
!
      IF (Hout(idMtls,ng)) THEN
        scale=1.0_r8
        gtype=gfactor*w3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idMtls), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 0, N(ng), scale,         &
#    ifdef MASKING
     &                     GRID(ng) % rmask,                            &
#    endif
     &                     MIXING(ng) % tl_gls(:,:,:,NOUT),             &
     &                     SetFillVal = .FALSE.)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idMtls)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF

        scale=1.0_r8
        gtype=gfactor*w3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idVmLS), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 0, N(ng), scale,         &
#    ifdef MASKING
     &                     GRID(ng) % rmask,                            &
#    endif
     &                     MIXING(ng) % tl_Lscale)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idVmLS)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#    ifdef GSL_MIXING
        scale=1.0_r8
        gtype=gfactor*w3dvar
        status=nf_fwrite3d(ng, iTLM, TLM(ng)%ncid, TLM(ng)%Vid(idVmKP), &
     &                     TLM(ng)%Rindex, gtype,                       &
     &                     LBi, UBi, LBj, UBj, 0, N(ng), scale,         &
#     ifdef MASKING
     &                     GRID(ng) % rmask,                            &
#     endif
     &                     MIXING(ng) % tl_Akp)
        IF (FoundError(status, nf90_noerr, __LINE__,                    &
     &                 __FILE__)) THEN
          IF (Master) THEN
            WRITE (stdout,10) TRIM(Vname(1,idVmKP)), TLM(ng)%Rindex
          END IF
          exit_flag=3
          ioerror=status
          RETURN
        END IF
#    endif
      END IF
#   endif
#  endif
# endif
!
!-----------------------------------------------------------------------
!  Synchronize tangent NetCDF file to disk to allow other processes
!  to access data immediately after it is written.
!-----------------------------------------------------------------------
!
      CALL netcdf_sync (ng, iTLM, TLM(ng)%name, TLM(ng)%ncid)
      IF (FoundError(exit_flag, NoError, __LINE__,                      &
     &               __FILE__)) RETURN

# ifdef SOLVE3D
      IF (Master) WRITE (stdout,20) KOUT, NOUT, TLM(ng)%Rindex
# else
      IF (Master)  WRITE (stdout,20) KOUT, TLM(ng)%Rindex
# endif
!
  10  FORMAT (/,' TL_WRT_HIS - error while writing variable: ',a,/,14x, &
     &        'into tangent NetCDF file for time record: ',i4)

# ifdef SOLVE3D
  20  FORMAT (3x,'TL_WRT_HIS   - wrote tangent  fields (Index=', i1,    &
     &        ',',i1,') into time record = ',i7.7)
# else
  20  FORMAT (3x,'TL_WRT_HIS   - wrote tangent  fields (Index=', i1,    &
     &        ') into time record = ',i7.7)
# endif

#else
      SUBROUTINE tl_wrt_his
#endif
      RETURN
      END SUBROUTINE tl_wrt_his
